Gang count refers to side-by-side device positions, not the number of plug sockets. A receptacle with two plug sockets can occupy one gang. Choose a 1-gang plate for one device position, a 2-gang plate for two, and so on.
These plates are designed for standard U.S. wall boxes. Check the selected plate’s outer dimensions, openings and mounting positions against your existing layout. For five positions, select 5 Gang in the 1–5 gang Decora wall-plate listing.